1. Field of the invention
This invention relates to a module of the parallelepipedal box type with an openable front face and containing several parallel and mobile supports, called cases, for supporting purposes, coiled optical fiber loops and fiber connectors.
For example the module can constitute a junction box in a cable-television distribution network so as to connect first optical fibers emerging from plural elementary cables of a multiple cable connected to a teledistribution central station, to second fibers connected with videocommunication installations in subscriber's homes. The module thereby serves, on one hand, to protect the different connections between fibers, and, on the other hand, to dispose of fiber loops required for the preparation, repair and modification of the connections between fibers. Such a module is very often attached to a vertical column in a building and, by its very nature, must not be voluminous, while enabling access to fiber loops situated at the side of the supports and manipulation of the connectors.
2. Description of the Prior Art
According to European patent application No. 0,146,478, three different assemblies of rectangular supports in the box are envisaged. The box comprises an openable front face through which the supports can be displaced one by one towards the outside of the box. According to a first assembly, the supports are laid out perpendicular to the front face of the box, and are individually pivotable around an axis which is parallel with the front face and perpendicular to the supports and to the two longitudinal sidewalls of the box. The first assembly is also envisaged in European patent application No. 0,215,668--corresponding to U.S. Pat. No. 4,792,203--which deals with supports having only one fiber-to-fiber connector, completed by a spare connector and a connector with one intermediary fiber, called a jumper. According to a second assembly, the supports are laid out parallel with the front face of the box, and are respectively pivotable around individual axes of rotation which are parallel with the front face and are located along longitudinal edges of the supports and aligned on a plane that is oblique to the front face of the box. Finally, according to a third assembly, the supports are each mounted slidably and perpendicular to the front face of the box.
By definition, the front face of the box is directly accessible to an operator, especially when a rear face of the box which is parallel with the front face, is fixed to a wall along which are channelled the cables and, if necessary, individual optical fibers. Consequently, for the three support assemblies disclosed in European patent application No. 0,146,478, extraction of one of the supports towards the outside of the box by pivoting, or rotation, or sliding, makes access to the inside of the box very difficult, particularly to the rear face of the box where the fibers are fanned out from cables. In fact, the gap between the supports should be small so as to reduce the bulkiness of the box. The operator's fingers cannot then reach the bottom of the box without risking involuntarily disconnecting fibers or weakening the optical fibers by pinching or twisting them.
For these reasons, a similar support embodying European patent application No. 0,146,478 does not support loops of first fibers coming from a same first cable and loops of second fibers coming from a same second cable and the connectors supported by the support only connect the aforesaid fibers, and not fibers coming from other cables or supports.
Furthermore, when the box only comprises a small number of supports, e.g. 2 to 5 supports, the thickness of the supports when stacked is less than the width or length of the supports to the extent that it is preferable to lay out the supports parallel with the wall and therefore to the openable front face in the box, in order to restrict the thickness of the box, particularly when the box is located in a corridor. Such a laying out of supports is in keeping with the second assembly according to FIGS. 2a and 2b of European patent application No. 0,146,478. However, this second assembly provides, beyond the above mentioned drawbacks, very difficult access to supports with pivoting axes that are far away from the front face and therefore close to the rear face of the box, and a dimension following a direction parallel with the box faces and therefore perpendicular to the pivoting axis that is greater than necessary, since the individual pivoting axes are substantially disposed on a plane that is oblique to the faces of the box.